These help reveal how our sensory systems work. Magicians use their intuitions to create the same things, and we can learn from them. Article in Scientific American this month.

How do magicians fool us? They use special effects, optical illusions, the most powerful weapon is the cognitive illusions, the manipulation, the channeling, the misdirection of attention and even memory.

[Watch it! That one blew me away.] A driver will be driving down the road looking for cars, not noticing cyclists and such. Now a Whodunnit video:

Is everything an illusion? The answer is yes. And no one has put this better than the famous philosopher, Keanu Reeves. Even after Neo picks the red pill, everything is still the result of electric impulses being transmitted and perceived by the brain. Our perception of the world is entirely illusion, everything we see is often very far from its reality.